DESCRIPTION: (provided by the applicant): Malaria remains the most prevalent vector-borne disease of humans with estimates of infection ranging from 270 to 488 million persons annually. Since species of anopheline mosquitoes have different vectoring capacities, distributions, habitat requirements, etc., the success of malaria control programs relies, in part, on a thorough knowledge of the identity, behavior, and ecology of vectors. Unlike Africa, where two or three species are responsible for most transmission of human Plasmodium, the epidemiology of malaria in the Americas is more complex due, in part, to the diversity of potential vectors and the number of cryptic species (species that cannot be distinguished easily by morphology) of anopheline mosquitoes. This complexity, and the difficulty of identifying species accurately, has stymied research efforts that require large sample sizes of multiple species. Studies that census large numbers of species in ecologically complex regions, and correlate habitat variables with species distributions are virtually absent from the New World. However, with recently available molecular methods for identifying Neotropical anophelines, investigations of vector identity, distribution, and ecology are now possible. This project addresses one of the main entomological gaps in our understanding of the epidemiology of malaria in the New World, the spatial and temporal elationship between breeding site habitat variables and anopheline species distribution patterns. Our primary hypothesis s that certain key habitat parameters of breeding sites predict the distribution of species in a particular region. The specific aims are to: 1) determine the distribution of anopheline species in a variety of breeding sites throughout a region where malaria is endemic, the ecology of the region is complex, and the diversity of anopheline mosquitoes is high, 2) determine the seasonal and yearly stability of species distributions in breeding sites, 3) describe the ecological profiles of Lnopheline breeding sites and correlate these with species distribution patterns, 4) develop DNA-based methods for identifying species. Although this study will provide important information regarding the epidemiology of malaria in a region of Bolivia, this project has more than simply local significance. This project will serve as a model for examining and understanding vector dynamics in other areas of the Americas where there is great diversity of potential vector species and ecological habitats.